As long as the sleeve is long enough, the stock torque is fine. But it's not an absolute requirement for the aftermarket bushings with good hardware either.
The original bushings were entirely different in design, not just material. The big torque numbers were used at least in part to literally dig the serrated ends of the inner sleeves into the metal to anchor the inner sleeves mechanically to the mounting points, so that it was the vulcanized rubber bushings that was twisted between the inner and outer sleeves to allow for suspension movement.
I'm one of those that likes to leave them on the loose side though, and judge proper tightness by the shape of the ears of the shackle and hangers as they squeeze down on the bushing flanged ends.
I don't like bending the ears in to crush the bushings, and don't like to crush the bushings to the point they're getting squeezed out.
All this loose talk though, only applies if you have perfectly good (or new) locking nuts on the hardware. If the nuts can loosen over time, such as if you continued to use original nuts that have been run up and down a time or three, then leaving things even slightly loose will eventually (or sooner) end up with dangerously loose hardware. So if you have to use stock hardware, run them up tight.
But better yet would be new hardware. At least the nuts.
So the factory torque is not a requirement with poly bushings, but it can be a good guide.
But it should not hurt anything either, because eventually the inner metal sleeve will stop further compression of the bushings and lock things down.
Some other suggestions:
1. Always do your final torque with the tires on the ground and the full weight of the truck on the suspension.
2. Always lube the bushing flanges (and all the other parts as well) with a good thick grease, such as the silicone stuff the polyurethane bushing manufacturers suggest.
Should not be petroleum based grease, but in a pinch I've used it and it has not degraded the poly. But it can in theory.
3. Remember to put the shackle/spring eye bolt in from the backside.
4. My preferred bolt direction for the frame mounts is the opposite, with the heads facing outward (and visible) with the threads and nuts facing in and protected inside the pocket area of the hangers. Most Broncos came from the factory this way, but I think some were put in the other way. I see more and more that way and it always seems out of place to me.
Paul
